Have names on the spheres built by rgl package plot3d

Is there a way to have the names shown when use plot3d(rgl) in R to build a 3d graph, cause it's hard to locate which entry the sphere belongs to when I have many spheres to plot on the same coordinate. For example, I have the data:

x y z
A 0.1 -0.5 3.2
B -1.1 1.2 0.8
C 2.0 2.1 0.6
......

plot3d(data,type="s",radius=0.025)

But, I want to have the name A, B, C shown on the graph as it's easier to observe.
Or to have the name shown only when I put the mouse onto one specific sphere.
I have tried to use different colors, but when I have like 20 spheres, it seems it will run out of colors or colors are too close to distinguish.